The present application relates to a display device with touch detection of an electrostatic capacitance type, a drive circuit and a driving method used for the device, and an electronic unit having such a display device with a touch detection.
In recent years, attention is paid to a display device to which a contact detecting device called a touch panel is attached or with which a touch panel is integrated. The user enters information using various button images or the like displayed in the display device instead of normal mechanical buttons. Since such a display device having the touch panel does not need input devices such as a keyboard, a mouse, and a keypad, the display device is being increasingly used in not only a computer but also a portable information terminal such as a cellular phone.
One of the touch detecting methods is a capacitive touch detecting method. For example, in Japanese Unexamined Patent Application Publication No. 2009-244958, a display device is proposed, in which a common electrode for display that is originally provided for the display device is also used as one of a pair of electrodes for a touch sensor, and the other electrode (touch detection electrode) is disposed so as to intersect the common electrode. An electrostatic capacitance is formed between the pair of electrodes for a touch sensor, and changes according to an external proximity object. In the display device, a display operation is performed by sequentially applying a drive signal to the common electrode and performing a line-sequential scan, and a touch detecting operation is performed by analyzing a touch detection signal which appears in the touch detection electrode in accordance with the drive signal.